The first scanner customized for computer use is the drum scanner. The scanner was developed in 1957 in the United States by a team of engineers that Russell A. Kirsch led. However, the scanners became popular in the 1990s and have remained consistent in the market even after the advancement of digital capture devices.
Modern computer scanners are the successors of the initial telephotography and fax input devices that came to use in the 19th century. Telephotography is a technology that deals with telegraphs where images are transmitted. The method of telephotography involved phone or radio signals with varying intensities that depict specific colors and tones to form an image.
The initial image to be scanned was a picture of Russell Kirsch’s kid called Walden Kirsch, who was three months old at the time. The photograph was generated by a drum scanner producing a black and white image with a 5 square centimeter size and 176 pixels resolution, which was a highly defining moment in image scanners’ development history. The picture remains the first photorealistic image to be produced and is famous to date.
Scanners have slowly but surely advanced into modern devices that are in use today, passing through different scanning technologies and models, resulting in more types of image scanners.
Functionality of Telephotography
Telephotographers left a large gap unattended because of limitations in bandwidth over simple wires making the resolution of produced images extremely poor. On the other hand, the device employed in early photography was huge, consuming a lot of space with a high energy requirement. This equipment was exceptionally drum scanners because flatbeds were yet to be developed. The limitations in the initial scanners prompted engineers to be innovative in the field, which led to the emergence of modern fax machines and scanners, which are closely related technologies.
Types of scanners
- Drum Scanners
These were the initial scanners ever to be developed in the world of scanning. They capture image details using photomultiplier tubes (PMT) instead of the charge-coupled device (CCD), which are arrays in inexpensive film scanners and flatbed scanners. They contain an acrylic cylinder called the scanner drum where original transmissive and reflective documents are placed and rotated at fast speeds of 120 or 60 rotations per minute (rpm) as they are scanned before precision optics to provide image details to the PMT. Drum scanners are still in the market to date since they have been advanced to capture top-quality images with 12 000 pixels per inch (PPI), allowing them to be used in the film works. They are also costly, costing about tens of thousands of dollars to a hundred thousand.
- Sheet-fed Scanners
These scanners employed simplified optics, making them become part of earlier massively produced scanners. Microtek introduced the initial model of these scanners with a capability of 300 DPI producing black and white images in 1985. These scanners are currently being used to scan loose sheets of paper, mainly in businesses to scan office documents.
- Flatbed Scanners
These scanners had more complicated capabilities and mechanics and became available for users in the late 1980’s and remained popular until the mid-1990s. The initial flatbed scanner was manufactured in the early 1970s to transform printed materials into digitized text by Ray Kurzweil. The scanner had the capability of scanning only on a horizontal strip that must have been less than two-inch-high with a memory of fewer than 64 kilobytes. Later, the scanner’s memory capacity and resolution were improved by engineers allowing it to capture images with the size of 9600 dpi. They Were distributed by companies like HP, Acer, and Microtek, offering 600 DPI or more, and later color versions became available. By the year 2000, flatbed scanners had become more reliable and cost-effective such as the Panini vision x driver.
Types of Flatbed Scanners
These scanners are of two major types; Contact Image Sensor (CIS) and Charge-Coupled Device (CCD). The CIS scanners have a more advanced technology employed for entry-level large-format, low-power, and portable scanning. They draw the image sensor very close to the object of focus and have a short warm-up time. These scanners are also more reliable since they don’t require frequent calibration but have poor color quality and resolution.
CCD scanners are made of a line of sensors that generate an electrical charge when touched by light. The electrical charge is then transformed into a digital value to produce an image. Many flatbed scanner consumers prefer CCD scanners, although they have some drawbacks. Even if the CCD scanners have many colors and are fast, they require constant calibration and can’t capture huge pictures.
Importance of Scanners
Until the development of digital cameras, many people required scanners to scan pictures for emailing and storing them in a Personal Computer. Scanning, therefore, assisted people in preserving history through the permanent storage of images in computers. Digital devices, however, have the requirement for scanners as cost-effective all-in-one fax and printer machines have reduced the request for object scanning.